1996 Ford Windstar 3.8L

A strange thing happened last night...After driving for about 1/2 hr, I stopped my van and put it park. It simply will not shift out of park and I had to have it towed to a shop. The van has 126,000 miles and I have been the sole ownwer performing regular service.
Any suggestions on why this might be happening?

Check your fuse for brake lights.Usually when that happens you can turn ignition to on position and pull shift lever to neutral and start.Hope this helps.